Use of fluoroscopically guided intra-articular hip injection in differentiating the pain source in concomitant hip and lumbar spine arthritis.

UNLABELLED: We retrospectively tested the effectiveness of fluoroscopically guided intra- articular hip injection in differentiating the pain generator in patients with atypical lower extremity pain and concomitant radiographic hip and spine arthritis. After the hip injection, 74 of 83 patients had pain relief (pain score improvement, 7.2 to 2.7) and functional improvement (Harris hip score [HHS] improvement, 54.3 to 80.4). Of those 74 patients, 50 (mean preoperative HHS, 60.3) went on to hip arthroplasty (for 48 of these 50, mean HHS increased to 84.4); the other 24 patients are being treated nonoperatively so far. The 11 patients who did not experience pain relief (9 after initial injection plus 2 after total hip arthroplasty) were found to have spinal pathology and were treated accordingly. STATISTICS: sensitivity, 100%; specificity, 81%; positive predictive value, 97%; negative predictive value, 100%.